Past as Prologue-Use of Rubella Vaccination Program Lessons to Inform COVID-19 Vaccination.

The rapid rollout of vaccines against COVID-19 as a key mitigation strategy to end the global pandemic might be informed by lessons learned from rubella vaccine implementation in response to the global rubella epidemic of 1963-1965. That rubella epidemic led to the development of a rubella vaccine that has been introduced in all but 21 countries worldwide and has led to elimination of rubella in 93 countries. Although widespread introduction and use of rubella vaccines was slower than that for COVID-19 vaccines, the process can provide valuable insights for the continued battle against COVID-19. Experiences from the rubella disease control program highlight the critical and evolving elements of a vaccination program, including clearly delineated goals and strategies, regular data-driven revisions to the program based on disease and vaccine safety surveillance, and evaluations to identify the vaccine most capable of achieving disease control targets.

Progress Toward Rubella and Congenital Rubella Syndrome Control and Elimination - Worldwide, 2012-2020.

Rubella virus is a leading cause of vaccine-preventable birth defects and can cause epidemics. Although rubella virus infection usually produces a mild febrile rash illness in children and adults, infection during pregnancy, especially during the first trimester, can result in miscarriage, fetal death, stillbirth, or an infant born with a constellation of birth defects known as congenital rubella syndrome (CRS). A single dose of rubella-containing vaccine (RCV) can provide lifelong protection against rubella (1). The Global Vaccine Action Plan 2011-2020 (GVAP) included a target to achieve elimination of rubella in at least five of the six World Health Organization (WHO) regions* by 2020 (2), and WHO recommends capitalizing on the accelerated measles elimination activities as an opportunity to introduce RCV (1). This report updates a previous report (3) and summarizes global progress toward control and elimination of rubella and CRS from 2012, when accelerated rubella control activities were initiated, through 2020. Among 194 WHO Member States, the number with RCV in their immunization schedules has increased from 132 (68%) in 2012 to 173 (89%) in 2020; 70% of the world's infants were vaccinated against rubella in 2020. Reported rubella cases declined by 48%, from 94,277 in 2012 to 49,136 in 2019, and decreased further to 10,194 in 2020. Rubella elimination has been verified in 93 (48%) of 194 countries including the entire Region of the Americas (AMR). To increase the equity of protection and make further progress to eliminate rubella, it is important that the 21 countries that have not yet done so should introduce RCV. Likewise, countries that have introduced RCV can achieve and maintain rubella elimination with high vaccination coverage and surveillance for rubella and CRS. Four of six WHO regions have established rubella elimination goals; the two WHO regions that have not yet established an elimination goal (the African [AFR] and Eastern Mediterranean [EMR] regions) have expressed a commitment to rubella elimination and should consider establishing a goal.

Progress Toward Rubella Elimination - Western Pacific Region, 2000-2019.

Rubella is the leading vaccine-preventable cause of birth defects. Rubella typically manifests as a mild febrile rash illness; however, infection during pregnancy, particularly during the first trimester, can result in miscarriage, fetal death, or a constellation of malformations known as congenital rubella syndrome (CRS), commonly including one or more visual, auditory, or cardiac defects (1). In 2012, the Regional Committee of the World Health Organization (WHO) Western Pacific Region (WPR)* committed to accelerate rubella control, and in 2017, resolved that all countries or areas (countries) in WPR should aim for rubella elimination† as soon as possible (2,3). WPR countries are capitalizing on measles elimination activities, using a combined measles and rubella vaccine, case-based surveillance for febrile rash illness, and integrated diagnostic testing for measles and rubella. This report summarizes progress toward rubella elimination and CRS prevention in WPR during 2000-2019. Coverage with a first dose of rubella-containing vaccine (RCV1) increased from 11% in 2000 to 96% in 2019. During 1970-2019, approximately 84 million persons were vaccinated through 62 supplementary immunization activities (SIAs) conducted in 27 countries. Reported rubella incidence increased from 35.5 to 71.3 cases per million population among reporting countries during 2000-2008, decreased to 2.1 in 2017, and then increased to 18.4 in 2019 as a result of outbreaks in China and Japan. Strong sustainable immunization programs, closing of existing immunity gaps, and maintenance of high-quality surveillance to respond rapidly to and contain outbreaks are needed in every WPR country to achieve rubella elimination in the region.

Combining serological and contact data to derive target immunity levels for achieving and maintaining measles elimination.

BACKGROUND: Vaccination has reduced the global incidence of measles to the lowest rates in history. However, local interruption of measles virus transmission requires sustained high levels of population immunity that can be challenging to achieve and maintain. The herd immunity threshold for measles is typically stipulated at 90-95%. This figure does not easily translate into age-specific immunity levels required to interrupt transmission. Previous estimates of such levels were based on speculative contact patterns based on historical data from high-income countries. The aim of this study was to determine age-specific immunity levels that would ensure elimination of measles when taking into account empirically observed contact patterns. METHODS: We combined estimated immunity levels from serological data in 17 countries with studies of age-specific mixing patterns to derive contact-adjusted immunity levels. We then compared these to case data from the 10 years following the seroprevalence studies to establish a contact-adjusted immunity threshold for elimination. We lastly combined a range of hypothetical immunity profiles with contact data from a wide range of socioeconomic and demographic settings to determine whether they would be sufficient for elimination. RESULTS: We found that contact-adjusted immunity levels were able to predict whether countries would experience outbreaks in the decade following the serological studies in about 70% of countries. The corresponding threshold level of contact-adjusted immunity was found to be 93%, corresponding to an average basic reproduction number of approximately 14. Testing different scenarios of immunity with this threshold level using contact studies from around the world, we found that 95% immunity would have to be achieved by the age of five and maintained across older age groups to guarantee elimination. This reflects a greater level of immunity required in 5-9-year-olds than established previously. CONCLUSIONS: The immunity levels we found necessary for measles elimination are higher than previous guidance. The importance of achieving high immunity levels in 5-9-year-olds presents both a challenge and an opportunity. While such high levels can be difficult to achieve, school entry provides an opportunity to ensure sufficient vaccination coverage. Combined with observations of contact patterns, further national and sub-national serological studies could serve to highlight key gaps in immunity that need to be filled in order to achieve national and regional measles elimination.

Progress Toward Rubella and Congenital Rubella Syndrome Control and Elimination - Worldwide, 2000-2018.

Rubella is a leading cause of vaccine-preventable birth defects. Although rubella virus infection usually causes a mild febrile rash illness in children and adults, infection during pregnancy, especially during the first trimester, can result in miscarriage, fetal death, stillbirth, or a constellation of birth defects known as congenital rubella syndrome (CRS). A single dose of rubella-containing vaccine (RCV) can provide lifelong protection (1). In 2011, the World Health Organization (WHO) updated guidance on the use of RCV and recommended capitalizing on the accelerated measles elimination activities as an opportunity to introduce RCV (1). The Global Vaccine Action Plan 2011-2020 (GVAP) includes a target to achieve elimination of rubella in at least five of the six WHO regions by 2020 (2). This report on the progress toward rubella and CRS control and elimination updates the 2017 report (3), summarizing global progress toward the control and elimination of rubella and CRS from 2000 (the initiation of accelerated measles control activities) and 2012 (the initiation of accelerated rubella control activities) to 2018 (the most recent data) using WHO immunization and surveillance data. Among WHO Member States,* the number with RCV in their immunization schedules has increased from 99 (52% of 191) in 2000 to 168 (87% of 194) in 2018†; 69% of the world's infants were vaccinated against rubella in 2018. Rubella elimination has been verified in 81 (42%) countries. To make further progress to control and eliminate rubella, and to reduce the equity gap, introduction of RCV in all countries is important. Likewise, countries that have introduced RCV can achieve and maintain elimination with high vaccination coverage and surveillance for rubella and CRS. The two WHO regions that have not established an elimination goal (African [AFR] and Eastern Mediterranean [EMR]) should consider establishing a goal.§.

Progress in Rubella and Congenital Rubella Syndrome Control and Elimination - Worldwide, 2000-2016.

Although rubella virus infection usually causes a mild fever and rash illness in children and adults, infection during pregnancy, especially during the first trimester, can result in miscarriage, fetal death, stillbirth, or infants with a constellation of congenital malformations known as congenital rubella syndrome (CRS) (1). Rubella is a leading vaccine-preventable cause of birth defects. Preventing these adverse pregnancy outcomes is the focus of rubella vaccination programs. In 2011, the World Health Organization (WHO) updated guidance on the preferred strategy for introduction of rubella-containing vaccine (RCV) into national immunization schedules and recommended an initial vaccination campaign, usually targeting children aged 9 months-14 years (1). The Global Vaccine Action Plan 2011-2020 (GVAP), endorsed by the World Health Assembly in 2012, includes goals to eliminate rubella in at least five of the six WHO regions by 2020 (2). This report updates a previous report (3) and summarizes global progress toward rubella and CRS control and elimination from 2000 to 2016. As of December 2016, 152 (78%) of 194 countries had introduced RCV into the national immunization schedule, representing an increase of 53 countries since 2000, including 20 countries that introduced RCV after 2012.

Hospital-based surveillance of congenital rubella syndrome in Indonesia.

Congenital rubella syndrome (CRS) has serious consequences, such as miscarriage, stillbirth, and severe birth defects in infants, resulting from rubella virus infection during pregnancy. However, rubella vaccine has not yet been implemented in Indonesia. This study aimed (1) to estimate the incidence of CRS in Indonesia, (2) describe the clinical features of CRS at our referral hospital, and (3) pilot a CRS surveillance system to be extended to other hospitals. We conducted a 4-month prospective surveillance study of infants aged <1 year with suspected CRS in 2013 at an Indonesian hospital. Infants with suspected CRS were examined for rubella-specific IgM antibody or rubella IgG antibody levels. Of 47 suspected cases of CRS, 11/47 (23.4%), 9/47 (19.1%), and 27/47 (57.5%) were diagnosed as laboratory-confirmed, clinically compatible, and discarded CRS, respectively. The most common defects among laboratory-confirmed CRS cases were hearing impairment (100%), congenital cataracts (72.7%), microcephaly (72.7%), and congenital heart defects (45.5%). CONCLUSION: The number of laboratory-confirmed CRS cases among Indonesian infants is high. Furthermore, hearing impairment is the most common clinical feature of CRS in infants. Our findings indicate the importance of implementation of rubella vaccine in Indonesia. Conducting hospital-based surveillance of CRS in other hospitals in Indonesia may be appropriate. What is Known: •Congenital rubella syndrome (CRS) has serious consequences in infants resulting from rubella virus infection during pregnancy. •The incidence of CRS in most developed countries has greatly decreased since implementation of rubella vaccination. •Rubella vaccine has not yet been implemented in many developing countries. What is New: •The number of laboratory-confirmed CRS cases among Indonesian infants was high. •Implementation of rubella vaccine into immunization programs in Indonesia is important because of the high number of CRS cases. •Our study highlights the need for ongoing prospective surveillance of CRS in Indonesia.

Synthesis of Evidence to Characterize National Measles and Rubella Exposure and Immunization Histories.

Population immunity depends on the dynamic levels of immunization coverage that countries achieve over time and any transmission of viruses that occur within the population that induce immunity. In the context of developing a dynamic transmission model for measles and rubella to support analyses of future immunization policy options, we assessed the model inputs required to reproduce past behavior and to provide some confidence about model performance at the national level. We reviewed the data available from the World Health Organization (WHO) and existing measles and rubella literature for evidence of historical reported routine and supplemental immunization activities and reported cases and outbreaks. We constructed model input profiles for 180 WHO member states and three other areas to support disease transmission model development and calibration. The profiles demonstrate the significant variability in immunization strategies used historically by regions and member states and the epidemiological implications of these historical choices. The profiles provide a historical perspective on measles and rubella immunization globally at the national level, and they may help immunization program managers identify existing immunity and/or knowledge gaps.

Characterization of the Risks of Adverse Outcomes Following Rubella Infection in Pregnancy.

Although most infections with the rubella virus result in relatively minor sequelae, rubella infection in early pregnancy may lead to severe adverse outcomes for the fetus. First recognized in 1941, congenital rubella syndrome (CRS) can manifest with a diverse range of symptoms, including congenital cataracts, glaucoma, and cardiac defects, as well as hearing and intellectual disability. The gestational age of the fetus at the time of the maternal rubella infection impacts the probability and severity of outcomes, with infection in early pregnancy increasing the risks of spontaneous termination (miscarriage), fetal death (stillbirth), birth defects, and reduced survival for live-born infants. Rubella vaccination continues to change the epidemiology of rubella and CRS globally, but no models currently exist to evaluate the economic benefits of rubella management. This systematic review provides an overall assessment of the weight of the evidence for the outcomes associated with rubella infections in the first 20 weeks of pregnancy. We identified, evaluated, and graded 31 studies (all from developed countries) that reported on the pregnancy outcomes of at least 30 maternal rubella infections. We used the available evidence to estimate the increased risks of spontaneous termination, fetal death, infant death, and CRS as a function of the timing of rubella infection in pregnancy and decisions about induced termination. These data support the characterization of the disability-adjusted life years for outcomes associated with rubella infection in pregnancy. We find significant impacts associated with maternal rubella infections in early pregnancy, which economic analyses will miss if they only focus on live births of CRS cases. Our estimates of fetal loss from increased induced terminations due to maternal rubella infections provide context that may help to explain the relatively low numbers of observed CRS cases per year despite potentially large burdens of disease. Our comprehensive review of the weight of the evidence of all pregnancy outcomes demonstrates the importance of including all outcomes in models that characterize rubella-related disease burdens and costs.

Systematic Review of the Manifestations of Congenital Rubella Syndrome in Infants and Characterization of Disability-Adjusted Life Years (DALYs).

Congenital rubella syndrome (CRS) continues to cause disability among unvaccinated populations in countries with no or insufficient rubella vaccine coverage to prevent transmission. We systematically reviewed the literature on birth outcomes associated with CRS to estimate the duration, severity, and frequency of combinations of morbidities. We searched PubMed, the Science Citation Index, and references from relevant articles for studies in English with primary data on the frequency of CRS manifestations for ≥20 cases and identified 65 studies representing 66 study populations that met our inclusion criteria. We abstracted available data on CRS cases with one or more hearing, heart, and/or eye defect following maternal rubella infection during the period of 0-20 weeks since the last menstrual period. We assessed the quality and weight of the available evidence using a modified Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Most of the evidence originates from studies in developed countries of cohorts of infants identified with CRS in the 1960s and 1970s, prior to the development of standardized definitions for CRS and widespread use of vaccine. We developed estimates of undiscounted disability-adjusted life years (DALYs) lost per CRS case for countries of different income levels. The estimates ranged from approximately 19 to 39 for high-income countries assuming optimal treatment and from approximately 29 to 39 DALYs lost per CRS case in low- and lower- middle-income countries assuming minimal treatment, with the lower bound based on 2010 general global burden of disease disability weights and the upper bound based on 1990 age-specific and treatment-specific global burden of disease disability weights. Policymakers and analysts should appreciate the significant burden of disability caused by CRS as they evaluate opportunities to manage rubella.

Identification of Serologic Markers for School-Aged Children With Congenital Rubella Syndrome.

BACKGROUND: Congenital rubella syndrome (CRS) case identification is challenging in older children since laboratory markers of congenital rubella virus (RUBV) infection do not persist beyond age 12 months. METHODS: We enrolled children with CRS born between 1998 and 2003 and compared their immune responses to RUBV with those of their mothers and a group of similarly aged children without CRS. Demographic data and sera were collected. Sera were tested for anti-RUBV immunoglobulin G (IgG), IgG avidity, and IgG response to the 3 viral structural proteins (E1, E2, and C), reflected by immunoblot fluorescent signals. RESULTS: We enrolled 32 children with CRS, 31 mothers, and 62 children without CRS. The immunoblot signal strength to C and the ratio of the C signal to the RUBV-specific IgG concentration were higher (P < .029 for both) and the ratio of the E1 signal to the RUBV-specific IgG concentration lower (P = .001) in children with CRS, compared with their mothers. Compared with children without CRS, children with CRS had more RUBV-specific IgG (P < .001), a stronger C signal (P < .001), and a stronger E2 signal (P ≤ .001). Two classification rules for children with versus children without CRS gave 100% specificity with >65% sensitivity. CONCLUSIONS: This study was the first to establish classification rules for identifying CRS in school-aged children, using laboratory biomarkers. These biomarkers should allow improved burden of disease estimates and monitoring of CRS control programs.

Global Progress Toward Rubella and Congenital Rubella Syndrome Control and Elimination - 2000-2014.

Rubella virus usually causes a mild fever and rash in children and adults. However, infection during pregnancy, especially during the first trimester, can result in miscarriage, fetal death, stillbirth, or a constellation of congenital malformations known as congenital rubella syndrome (CRS). In 2011, the World Health Organization (WHO) updated guidance on the preferred strategy for introduction of rubella-containing vaccine (RCV) into national routine immunization schedules, including an initial vaccination campaign usually targeting children aged 9 months-15 years . The Global Vaccine Action Plan endorsed by the World Health Assembly in 2012 and the Global Measles and Rubella Strategic Plan (2012-2020) published by Measles and Rubella Initiative partners in 2012 both include goals to eliminate rubella and CRS in at least two WHO regions by 2015, and at least five WHO regions by 2020 (2,3). This report updates a previous report and summarizes global progress toward rubella and CRS control and elimination during 2000-2014. As of December 2014, RCV had been introduced in 140 (72%) countries, an increase from 99 (51%) countries in 2000 (for this report, WHO member states are referred to as countries). Reported rubella cases declined 95%, from 670,894 cases in 102 countries in 2000 to 33,068 cases in 162 countries in 2014, although reporting is inconsistent. To achieve the 2020 Global Vaccine Action Plan rubella and CRS elimination goals, RCV introduction needs to continue as country criteria indicating readiness are met, and rubella and CRS surveillance need to be strengthened to ensure that progress toward elimination can be measured.

The path to eradication of rubella.

Since 1969, rubella and its harmful effect on fetuses infected in utero can be prevented by rubella vaccine, usually given in combination with measles vaccine. The rubella vaccine is highly protective both in children and in adults including women intending to become pregnant. Owing to the use of combined measles and rubella vaccines, congenital rubella infection has been eliminated from the Western Hemisphere and nearly all of Europe. Such combined vaccination is now being applied throughout the world, posing the possibility of eventual rubella eradication. The existence of viruses of animals related to rubella does not appear to be a barrier to eradication of the human virus. However, persistent rubella virus in infants infected in utero and of immunosuppressed patients with granulomas may pose a problem for eradication. Nevertheless, this review posits that eradication of rubella is now feasible if routine vaccination of infants and surveillance for chronic infection are correctly applied.

Estimates of the global burden of Congenital Rubella Syndrome, 1996-2019.

OBJECTIVES: Many countries introduced rubella-containing vaccination (RCV) after 2011, following changes in recommended World Health Organization (WHO) vaccination strategies and external support. We evaluated the impact of these introductions. METHODS: We estimated the country-specific, region-specific, and global Congenital Rubella Syndrome (CRS) incidence during 1996-2019 using mathematical modeling, including routine and campaign vaccination coverage and seroprevalence data. RESULTS: In 2019, WHO African and Eastern Mediterranean regions had the highest estimated CRS incidence (64 [95% confidence intervals (CI): 24-123] and 27 [95% CI: 4-67] per 100,000 live births respectively), where nearly half of births occur in countries that have introduced RCV. Other regions, where >95% of births occurred in countries that had introduced RCV, had a low estimated CRS incidence (<1 [95% CI: <1 to 8] and <1 [95% CI: <1 to 12] per 100,000 live births in South-East Asia [SEAR] and the Western Pacific [WPR] respectively, and similarly in Europe and the Americas). The estimated number of CRS births globally declined by approximately two-thirds during 2010-2019, from 100,000 (95% CI: 54,000-166,000) to 32,000 (95% CI: 13,000-60,000), representing a 73% reduction since 1996, largely following RCV introductions in WPR and SEAR, where the greatest reductions occurred. CONCLUSIONS: Further reductions can occur by introducing RCV in remaining countries and maintaining high RCV coverage.

Evidence used to support the achievement and maintenance of elimination of rubella and congenital rubella syndrome in the United States.

On 29 October 2004, an expert panel was convened to review the status of elimination of rubella and congenital rubella syndrome (CRS) in the United States. Primarily based on 5 types of information presented--epidemiology of reported cases, molecular epidemiology, seroprevalence, vaccine coverage, and adequacy of surveillance--the panel unanimously agreed that rubella virus is no longer endemic in the United States. Since 2004, new data continue to support the conclusion that elimination has been achieved and maintained. In documenting elimination in the United States, each of the 5 types of data provided evidence for elimination and collectively provided much stronger evidence than any one type could individually. As countries document the elimination of rubella and CRS, many sources and types of data will likely be necessary. Rigorous data evaluation must be conducted to look for inconsistencies among the available data. To maintain elimination, countries should maintain high vaccine coverage, adequate surveillance, and rapid response to outbreaks.

Virologic surveillance for wild-type rubella viruses in the Americas.

The goal of eliminating rubella from the Americas by 2010 was established in 2003. Subsequently, a systematic nomenclature for wild-type rubella viruses (wtRVs) was established, wtRVs circulating in the region were catalogued, and importations of wtRVs into a number of countries were documented. The geographic distribution of wtRVs of various genotypes in the Americas, interpreted in the context of the global distribution of these viruses, contributed to the documentation of rubella elimination from some countries. Data from virologic surveillance also contributed to the conclusion that viruses of genotype 2B began circulating endemically in the Americas during 2006-2007. Viruses of one genotype (1C), which are restricted to the Americas, will likely disappear completely from the world as they are eliminated from the Americas. Efforts to expand virologic surveillance for wtRVs in the Americas will also provide additional data aiding the elimination of rubella from the region. For example, identification of vaccine virus in specimens from rash and fever cases found during elimination can identify such cases as vaccine associated.

Guidelines for the documentation and verification of measles, rubella, and congenital rubella syndrome elimination in the region of the Americas.

In the region of the Americas, goals for the elimination of endemic measles and rubella/congenital rubella syndrome (CRS) by the year 2000 and 2010, respectively were established. The successful implementation of measles elimination strategies in the region of the Americas resulted in the interruption of endemic measles transmission in 2002 and tremendous progress toward rubella and CRS elimination. In October 2007, the 27th Pan American Sanitary Conference adopted Resolution CSP27.R2 urging member states to begin documenting and verifying the interruption of endemic transmission of the measles and rubella viruses in the Americas. To ensure a standardized approach for the process of documentation and verification, the Pan American Health Organization/World Health Organization (PAHO/WHO) developed a regional plan of action to guide countries and their national commissions as they prepare and consolidate evidence of the interruption of endemic measles and rubella transmission. This article summarizes the plan of action including the essential criteria and components of the guidelines.

Rubella vaccination of unknowingly pregnant women during mass campaigns for rubella and congenital rubella syndrome elimination, the Americas 2001-2008.

BACKGROUND: Due to the significant teratogenicity of rubella virus and the use of a live-attentuated vaccine, pregnancy is a contraindication of receipt of rubella vaccine (RCV). Data collected from several countries that have observed susceptible women who had received RCV during pregnancy documented that no infant with congenital rubella syndrome (CRS) has been born, so the risk is theoretical. As part of the regional initiative to eliminate rubella and CRS in the Americas, one of the key strategies was the vaccination of women of childbearing age. The implementation of mass vaccination campaigns targeting women of childbearing age in Argentina, Brazil, Costa Rica, Ecuador, El Salvador, and Paraguay provided an opportunity to further increase the body of knowledge on the safety of rubella vaccine if an unknowingly pregnant woman is vaccinated in early pregnancy. METHODS: Using a standard protocol, women who were unknowingly pregnant or become pregnant ≤ 30 days after receiving RCV were evaluated to determine immunity status (eg, susceptible, immune, and unknown) at the time of vaccination. Susceptible pregnant women were observed to determine the outcome of the pregnancy. For pregnancies that resulted in live births, serum samples were obtained from the newborn for rubella immunoglobulin (Ig) M antibody testing. If the newborn's serum sample was IgM positive, the infant was evaluated for manifestations of CRS. RESULTS: During the period 2001-2008, 48748253 women of childbearing age were vaccinated in the region of the Americas, 39542253 (81%) of whom were vaccinated in the 6 selected countries. Of these women, 30139 (0.07%) were pregnant or became pregnant ≤1 month after receiving vaccine and were followed up. On the basis of serological evaluation, 2894 (10%) women were classified as susceptible at the time of vaccination; of their pregnancies, 1980 (90%) resulted in a live birth. Sera from 70 (3.5%) of these infants were rubella IgM antibody positive, but none of the infants had features of CRS as a result of rubella vaccination. The maximum theoretical risk for CRS following rubella vaccination of susceptible pregnant women was 0.2%. Conclusions. The results of these studies from 6 select countries provides additional evidence showing an absence of risk of CRS associated with administering rubella vaccine shortly before or during pregnancy.

Feasibility of measles and rubella vaccination programmes for disease elimination: a modelling study.

BACKGROUND: Marked reductions in the incidence of measles and rubella have been observed since the widespread use of the measles and rubella vaccines. Although no global goal for measles eradication has been established, all six WHO regions have set measles elimination targets. However, a gap remains between current control levels and elimination targets, as shown by large measles outbreaks between 2017 and 2019. We aimed to model the potential for measles and rubella elimination globally to inform a WHO report to the 73rd World Health Assembly on the feasibility of measles and rubella eradication. METHODS: In this study, we modelled the probability of measles and rubella elimination between 2020 and 2100 under different vaccination scenarios in 93 countries of interest. We evaluated measles and rubella burden and elimination across two national transmission models each (Dynamic Measles Immunisation Calculation Engine [DynaMICE], Pennsylvania State University [PSU], Johns Hopkins University, and Public Health England models), and one subnational measles transmission model (Institute for Disease Modeling model). The vaccination scenarios included a so-called business as usual approach, which continues present vaccination coverage, and an intensified investment approach, which increases coverage into the future. The annual numbers of infections projected by each model, country, and vaccination scenario were used to explore if, when, and for how long the infections would be below a threshold for elimination. FINDINGS: The intensified investment scenario led to large reductions in measles and rubella incidence and burden. Rubella elimination is likely to be achievable in all countries and measles elimination is likely in some countries, but not all. The PSU and DynaMICE national measles models estimated that by 2050, the probability of elimination would exceed 75% in 14 (16%) and 36 (39%) of 93 modelled countries, respectively. The subnational model of measles transmission highlighted inequity in routine coverage as a likely driver of the continuance of endemic measles transmission in a subset of countries. INTERPRETATION: To reach regional elimination goals, it will be necessary to innovate vaccination strategies and technologies that increase spatial equity of routine vaccination, in addition to investing in existing surveillance and outbreak response programmes. FUNDING: WHO, Gavi, the Vaccine Alliance, US Centers for Disease Control and Prevention, and the Bill & Melinda Gates Foundation.

Guidance for isolation precautions for mumps in the United States: a review of the scientific basis for policy change.

The 2006 mumps resurgence in the United States raised questions about the appropriate isolation period for people with mumps. To determine the scientific basis for isolation recommendations, we conducted a literature review and considered isolation of virus and virus load in saliva and respiratory secretions as factors that were related to mumps transmission risk. Although mumps virus has been isolated from 7 days before through 8 days after parotitis onset, the highest percentage of positive isolations and the highest virus loads occur closest to parotitis onset and decrease rapidly thereafter. Most transmission likely occurs before and within 5 days of parotitis onset. Transmission can occur during the prodromal phase and with subclinical infections. Updated guidance, released in 2007-2008, changed the mumps isolation period from 9 to 5 days. It is now recommended that mumps patients be isolated and standard and droplet precautions be followed for 5 days after parotitis onset.